The next update from the National Hurricane Center is expected at 5 a.m.

Tropical Storm Isaac continued on its forecast track Saturday night, with the Treasure Coast and Lake Okeechobee still expecting tropical storm conditions by Sunday evening, according to the 2 a.m. Sunday update from the National Hurricane Center.

A tropical storm warning remains in effect south of Sebastian Inlet to Ocean Reef, with a tropical storm watch extending north from Brevard County to Flagler Beach.

Emergency Management officials across the Treasure Coast continue to monitor the storm's progress. No evacuations, school or government closings, or emergency shelter openings had been announced by Saturday evening. However, meetings were planned for Sunday to re-evaluate expected weather.

Weather forecasters are warning residents of the Treasure Coast to monitor weather information closely Sunday and Monday for reports of tornadoes. These dangerous funnel clouds often are associated with the storms in the outer bands of tropical weather, such as is being forecast for Martin, St. Lucie and Indian River counties.

Rain and wind will start to build Sunday morning, reaching maximum strength around sunset, said Matt Bragaw, meteorologist with the National Weather Service in Melbourne.

Martin and St. Lucie counties can expect sustained winds of 25 to 30 miles per hour, gusting to 40 to 45 mph Sunday afternoon and evening, Bragaw said.

Indian River and Okeechobee counties likely will experience sustained winds of 20 to 25 mph with gusts to 35 to 40 mph during that time, he added.

Anywhere from 3 to 5 inches of rain is expected on the Treasure Coast on Sunday, with rainfall expected to be heavier in Martin and St. Lucie counties, he said.

Winds will start to decrease by daybreak Monday, Bragaw said, but rain and thunderstorms associated with Isaac will continue to present a threat of flooding and tornadoes throughout the day.

On Saturday, Gov. Rick Scott declared a state of emergency in Florida because of the approaching storm. Saturday night, Republican leaders announced they were only going to officially open the Republican National Convention on Monday, then push back Monday's activities until Tuesday because of Isaac.

Palm Beach County declared a local state of emergency Saturday and some flights slated to leave Palm Beach International Airport on Sunday have been canceled.

At 2 a.m., the center of Tropical Storm Isaac was moving between the north coast of Cuba and Andros Island in the Bahamas with maximum sustained winds near 60 mph. It was moving toward the northwest at about 17 mph and that motion was expected to continue for the next 48 hours. Isaac was about 265 miles from Key West and was expected to strengthen.

The Florida Keys, along with the west coast of Florida from Bonita Beach south to Florida Bay, are under a hurricane warning with Isaac expected to be at or near hurricane strength when it reaches the Keys Sunday or Sunday night.

Dangerous surf and rip currents will affect the east coast of Florida and the Keys during the next couple of days.

What to expect on the Treasure Coast on Sunday and Monday

Sunday: Showers and storms will drop between 2-3 inches of rain on the Treasure Coast during daylight hours, plus another 1-2 inches when the worst weather arrives after sunset. Rainfall amounts will be heavier in Martin and St. Lucie counties, where sustained winds will reach 25-30 mph with gusts to 40-45 mph; Indian River County is expected to have sustained winds of 20-25 mph with gusts to 35-40 mph. Localized flooding may occur, and there is a chance that tornadoes may be formed by some of these storms.

Monday: Winds and rain will diminish over the Treasure Coast, with maximum sustained winds at 20-25 mph and top gusts at 30-35 mph. Another 1 inch of rain is expected.

Marine: Boating conditions will continue to worsen Sunday. Small craft should remain in port. Winds will be 15-20 knots from the northwest Sunday morning, increasing to 20-25 knots in the afternoon. Seas will be 8-9 feet and rough on the Intracoastal Waterway. There will be numerous showers and isolated thunderstorms. Tropical storm conditions are possible Sunday night, with east winds 20-25 knots and seas 11-12 feet, and continued rough conditions on the Intracoastal Waterway. Tropical storm conditions will be possible again Monday, with east winds 20-25 knots, seas 9-11 feet, rough on the Intracoastal and numerous showers and isolated thunderstorms.